1. Field of the Invention
The present invention relates to a transflective type liquid crystal display device. More specifically, the present invention relates to a transflective type liquid crystal display device that has sub-pixel electrodes.
2. Description of Related Art
Liquid crystal display devices are in widespread use as displays of mobile phones, car navigation systems, digital cameras, portable game devices, PDAs (Personal Digital Assistants), personal computers, and the like. The displaying scheme of the liquid crystal display panels is classified broadly into the following three types, i.e., a transmissive type, a reflective type, and a transflective type. The transmissive type is a displaying scheme in which a light source called a backlight is lit, such that light transmitting through a liquid crystal display panel carries out displaying. Hence, though the transmissive type exhibits high visibility in dark places, the visibility is poor in bright places. On the other hand, the reflective type is a displaying scheme in which light incident upon a liquid crystal display panel is reflected therefrom, to carry out displaying. Hence, though high visibility is achieved in bright places, the visibility is poor in dark places. The transflective type is a displaying scheme that combines both the functions of the transmissive type and the reflective type, and is capable of always providing a high visibility display by switching the display modes depending on the surrounding brightness. Owing to the excellent display characteristics thereof, the transflective type liquid crystal display devices are widely applied to portable or mobile equipment and the like.
In many transflective type liquid crystal display devices, the ECB (Electrically Controlled Birefringence) mode or the TN (Twisted Nematic) mode is employed. However, in response to recent increasing needs for higher contrast and a wider viewing angle, much attention is now focused on liquid crystal display devices of the vertical alignment (VA: Vertical Alignment) mode in which pixels are divided into a plurality of sub-pixel electrodes (sub-pixel regions) (for example, Japanese Unexamined Patent Application Publication No. 2005-266778).
Japanese Unexamined Patent Application Publication No. 2005-266778 discloses a structure in which a pixel region is divided into a plurality of sub-pixel electrodes, and the sub-pixel electrodes are connected by a narrow-width connecting portion. Further, a reflective conductive thin film that is a light-shielding conductive film is arranged so as to cover the connecting portion and part of the transmissive region at the location near the connecting portion.
It has now been discovered that, in accordance with Japanese Unexamined Patent Application Publication No. 2005-266778, in the transmissive region extending from the connecting portion, the liquid crystal alignment is disturbed in some cases, as being originated from a stepped structure that is resulted from the formation of the reflective conductive thin film. This results in an improper display state. Particularly, in the transflective type liquid crystal display device that has both the transmissive region and the reflective region, when the stepped portion enters the transmissive region side, there have been some cases in which the liquid crystal alignment is disturbed as being originated from the stepped portion formed by the transparent conductive thin film and the reflective conductive thin film, which results in an improper display state.